Snap switch with a separate leaf spring biasing member

Abstract

An electrical switch includes a movable contactor which is actuated by a push button to engage a movable contact with a normally-open contact. A spring yieldably resists depression of the push button and normally maintains a clearance between the push button and the contactor. The spring is superimposed relative to the connector and engages the latter to act as a heat conducting fin. A free end of the spring slides in a notch of the push button. In one embodiment, the spring produces a varying rate of resistance to depression of the button. In another embodiment, the spring urges the connector to its normal position in response to release of the button.

What is claimed as our invention is: 
     
       1. An electrical switch comprising: a housing,   first and second stationary terminals including first and second stationary terminal parts, respectively, disposed in said housing,   a normally-closed stationary contact and a normally-open stationary contact disposed in said housing and fixed to said first and second terminal parts, respectively,   a third terminal including a third stationary terminal part disposed in said housing,   a movable contactor disposed in said housing and including a base end and a free end, said base end being fixed to said third terminal part, said free end carrying movable contact means, said movable contactor being rockable to move said movable contact means alternately into engagement with said normally-closed and normally-open contacts, said movable contactor including an integral tongue having a free end engageable with a portion of said housing so as to normally urge said movable contactor into a normal position engaging said movable contact means with said normally-closed contact,     a push-button movably mounted on said housing and including outer and inner ends, said outer end being accessible from outside of said housing so as to be manually depressible for causing said inner end of said button to be moved inwardly, said inner end of said button positioned to face said movable contactor, and including a notch opening toward said movable contactor, and   a spring disposed in said housing for yieldably biasing said button in its non-depressed position such that a clearance is normally maintained between said inner end of said button and said movable contactor, said spring including a base end connected to said third terminal part and lying flush against said base end of said movable contactor, said spring disposed in superimposed relation to said movable contactor, and including a biasing section comprising: a first portion extending from said base part in spaced relation to said movable contactor,   a second portion extending toward said movable contactor and comprising a bent abutment portion normally spaced from said movable contactor by a distance less than said clearance and arranged to engage said movable contactor prior to engagement of said movable contactor by said inner end of said button when said button is depressed, whereby upon depression of said button said spring initially deforms about its base end and opposes depression of said button by a first force prior to engagement of said abutment portion with said movable contactor and thereafter said free end deforms about said abutment portion to oppose depression of said button by a second, larger force, and   a third portion extending away from said movable contactor and terminating in a free end of said spring, said free end being received in said notch of said button for sliding movement along a surface thereof.     
     
     
       2. A switch according to claim 1, wherein said spring is entirely disposed on a side of said movable contactor facing said button. 
     
     
       3. A switch according to claim 1, wherein said spring includes two said biasing sections spaced apart and disposed parallel to one another, said inner end of said buttom including two said notches for receiving said free end of each said biasing section. 
     
     
       4. A switch according to claim 1, wherein said surface of said notch is arcuate. 
     
     
       5. A switch according to claim 4, wherein said free end of said spring is rounded. 
     
     
       6. An electrical switch comprising: a housing,   first and second stationary terminals including first and second stationary terminal parts, respectively, disposed in said housing,   a normally-closed stationary contact and a normally-open stationary contact disposed in said housing and fixed to said first and second terminal parts, respectively,   a third terminal including a third stationary terminal part disposed in said housing,   a movable contactor disposed in said housing and including a base end and a free end, said base end being fixed to said third terminal part, said free end carrying movable contact means, said movable contactor being rockable to move said movable contact means alternately into engagement with said normally-closed and normally-open contacts, said movable contactor including an integral tongue having a free end engageable with a portion of said housing so as to normally urge said movable contactor into a position engaging said movable contact means with said normally-closed contact,     a push-button movably mounted on said housing and including outer and inner ends, said outer end being accessible from outside of said housing so as to be manually depressible for causing said inner end of said button to be moved inwardly, said inner end of said button positioned to face said movable contactor, and   a spring disposed in said housing for yieldably biasing said button to its non-depressed position such that a clearance is normally maintained between said inner end of said button and said movable contactor, said spring including a base end anchored in said housing, a button-engaging portion engaging said button, and an abutment portion normally spaced from said movable contactor by a distance less than said clearance and arranged to engage said movable contactor prior to engagement of said movable contactor by said inner end of said button when said button is depressed, whereby upon depression of said button said spring initially deforms about its base end and opposes depression of said button by a first force prior to engagement of said abutment portion with said movable contactor and thereafter said free end deforms about said abutment portion to oppose depression of said button by a second, larger force.   
     
     
       7. An electrical switch comprising: a housing,   first and second stationary terminals including first and second stationary terminal parts, respectively, disposed in said housing,   a normally-closed stationary contact and a normally-open stationary contact disposed in said housing and fixed to said first and second terminal parts, respectively,   a third terminal including a third stationary terminal part disposed in said housing,   a movable contactor disposed in said housing and including a base end and a free end, said base end being fixed to said third terminal part, said free end carrying movable contact means, said movable contactor being rockable to move said movable contact means alternately into engagement with said normally-closed and normally-open contacts, said movable contactor including an integral tongue having a free end engageable with a portion of said housing so as to normally urge said movable contactor into a normal position engaging said movable contact means with said normally-closed contact,     a push-button movably mounted on said housing and including outer and inner ends, said outer end being accessible from outside of said housing so as to be manually depressible for causing said inner end of said button to be moved inwardly, said inner end of said button positioned to face said movable contactor, and including a notch opening toward said movable contactor, and   a spring disposed in said housing for yieldably biasing said button in its non-depressed position such that a clearance is normally maintained between said inner end of said button and said movable contactor, said spring including a base end connected to said third terminal part and lying flush against said base end of said movable contactor, said spring disposed in superimposed relation to said movable contactor, and including a biasing section comprising: a first portion extending from said base part in spaced relation to said movable contactor,   a second portion extending toward said movable contactor, and   a third portion extending away from said movable contactor and terminating in a free end of said spring, said free end being received in said notch of said button for sliding movement along a surface thereof,     a portion of said spring underlying said movable contactor so as to be engageable with a side of the latter facing away from said button for urging said movable contactor to its normal position in which said movable contact means engages said normally closed contact when said button is in its non-depressed condition.   
     
     
       8. A switch according to claim 7, wherein said portion of said spring which underlies said movable contactor comprises said base end, said first portion, and said second portion; said third portion projecting toward said inner end of said button through an opening in said movable contactor. 
     
     
       9. An electrical switch comprising: a housing,   first and second stationary terminals including first and second stationary terminal parts, respectively, disposed in said housing,   a normally-closed stationary contact and a normally-open stationary contact disposed in said housing and fixed to said first and second terminal parts, respectively,   a third terminal including a third stationary terminal part disposed in said housing,   a movable contactor disposed in said housing and including a base end and a free end, said base end being fixed to said third terminal part, said free end carrying movable contact means, said movable contactor being rockable to move said movable  contact means alternately into engagement with said normally-closed and normally-open contacts, said movable contactor including a integral tongue having a free end engageable with a portion of said housing so as to normally urge said movable contactor into a position engaging said movable contact means with said normally-closed contact,     a push-button movably mounted on said housing and including outer and inner ends, said outer end being accessible from outside of said housing so as to be manually depressible for causing said inner end of said button to be moved inwardly, said inner end of said button positioned to face said movable contactor, and   a spring disposed in said housing for yieldably biasing said button to its non-depressed position such that a clearance is normally maintained between said inner end of said button and said movable contactor, said spring including a base end anchored in said housing, a button-engaging portion, and an abutment portion underlying said movable contactor so as to be engageable with a side of the latter facing away from said button for urging said movable contactor to its normal position in which said movable contact means engages said normally closed contact when said button is in its non-depressed condition.